<canvas width="150" height="150">
</canvas>

<script>
	const canvas = document.querySelector('canvas');
	const ctx = canvas.getContext('2d');
  ctx.fillRect(25, 25, 100, 100);
  ctx.clearRect(45, 45, 60, 60);
  ctx.strokeRect(50, 50, 50, 50);
</script>
